Latch relay motor structure

ABSTRACT

A clapper-type magnetic latch relay with electromagnetic operating means having a remanent magnet core with one end surface coupled with an optimum pole face area on one side of an air gap without sacrificing core diameter and coil winding relationship.

United States Patent Walter J. Richert Princeton, Ind. 18,054

Mar. 10, 1970 Aug. 10, 1971 AMF Incorporated Inventor Applv No. FiledPatented Assignee Luca RELAY MOTOR STRUCTURE 8 Claims, 7 Drawing Figs.

u.s Cl. 335/230, '3 35/254 Int. Cl H01! 7/08 Field of Search 335/203.

[ 56] References Cited UNITED STATES PATENTS 3,|95,023 7/1965Ueberschuss et al. 335/230 3,317,87l 5/1967 Adams 335/230 FOREIGNPATENTS 892,844 4/1962 Great Britain 335/230 Primary Examiner-G. HarrisAttorneys-George W. Price and Charles J. Worth ABSTRACT: A clapper-typemagnetic latch relay with elec tromagnetic operating means having aremanent magnet core with one end surface coupled with an optimum poleface area on one side of an air gap without sacrificing core diameterand coil winding relationship.

PATENTEI] AUG I own FIG. 2

FIG. 6

INVENTOR WALTER J. RICH T BYCQMQM AGENT LATCH RELAY MOTOR STRUCTURE Thisinvention relates generally to a magnetic latch relay of the type shown,described and claimed in my US. Pat. No. 3,470,510 which issued Sept.30, 1969 and is assigned to the same assignee as is the presentapplication. More particularly, the present invention is concerned withreducing reluctance resulting from the relationship of the partsproviding flux paths.

As disclosed in my aforenoted patent, the core of the electromagnetcould be made fully or in part of a material with remanentcharacteristics. When the core is polarized, the flux path through theremanent magnet material extends axially relative to the core. Where thecore, especially when made fully of a remanent magnet material, extendsthrough a bracket member of the frame also providing part of a fluxpath, the flow of flux from the bracket member must at thatintersection'cross at least some of the flux lines or lines of magneticforce of the core which then appears as reluctance. This, of course,reduces the motoring and latching effect of the available flux on thearmature.

In my earlier configuration, the pole face area is dictated by thediameter of the core and determines the working airgap of a given designwhich is an operating limitation. It also has been found that magneticflux or flux lines fed into softer magnetic materials will distributemore uniformly than flux entering harder magnetic materials with greaterremanent characteristics which have been exposed to a magnetizing fieldof a different orientation.

Accordingly, an object of the present invention is to provide a magneticlatch relay in a manner which facilitates construction and reduces cost.

Another'object of the present invention is to provide the foregoingrelay having improved flux paths.

And another object of the present invention is to provide the foregoingrelay having an optimum pole face area without sacrificing core diameterand coil winding relationships.

The foregoing and other objects and advantages will appear more fullyhereinafter from a consideration of the detailed description whichfollows, taken together with the accompanying drawings wherein severalembodiments of the invention are illustrated by way of example. It is tobe expressly understood, however, that the drawings are for illustrationpurposes only and are not to be construed as defining the limits of theinvention.

FIG. 1 is a side elevational view of a relay made in accordance with thepresent invention.

FIG. 2 is a fragmentary sectional view taken on line 2-2 of FIG. I withthe armature removed.

FIG. 3 is a side elevational view of a modified relay construction, inaccordance with the present invention, with the header removed.

.FIG. 4 is a sectional view taken on line 4-4 of FIG. 3 with the headerremoved.

FIGS. 5,6 and 7 are views similar to FIG. 3 each illustrating adifferent modified construction.

Referring now to the drawings and particularly to FIGS. 1 and 2, a-relaymade in accordance with the present invention is provided with agenerally C-shaped support means or frame 10 having a base member II, abracket member 14 and a permanent magnet 16 to provide magnetmeanstherebetween. The members II and 14, which are of soft magneticmaterial, are spaced from and substantially parallel to each other. Basemember 11 has at one end an armature-supporting leg 12 which extendsupwardly past member 14, and at its other end connecting means which, inthis instance, is an upwardly extending leg or flange l3. Bracket member14 has at one end a leg 15 which depends toward the base member 11.

Legs 12 and 15 are spaced from and substantially parallel to each other.The permanent magnet 16 is disposed in the space between and connectedto the legs 12 and 15, thereby connecting the base and bracket members11 and 14 together. Therefore, frame 10 includes a permanent magnetmaterial.

To complete the general frame structure, an armature retainer member 17is connected to the side of leg 12 opposite from the magnet 16. Thelower end of retainer 17 is provided with a projection 18, which extendstherefrom in a direction away from magnet 16, for retaining one end of atail spring 19 as shown.

The novel relay is provided with an actuating means or electromagnetic20 having a coil 21 and a core 22 which is suitably connected,preferably by welding, at its ends between the base member 11 and thebracket member 14. The bracket member 14 is provided with an offsetportion 24 of predetermined or desired size at the end of the core 22,the upper surface of which forms a pole face 23 which is ofsubstantially greater area than the end or cross-sectional area of thecore. The core 22 is of a relatively hard remanent magnet material whilethe bracket 14 providing the pole face 23 is of soft magnetic material.

The permanent magnet 16 together with legs 12 and 15 are disposed on oneside of the electromagnet 20, while a terminal header or block 25 isprovided on the other side thereof and is connected to the flange 13 inany suitable manner well known in the art. The header 25 supports atleast one fixed contact 26 or 27 which are spaced from each other andhave terminal connection portions. The coil 21 is considered to be ofsimple construction wherein a single extent of wire is used for the coilwindings and a pair of terminals 28 and 29, which are fixedly supportedby the header 25, are provided for the wound wire. Coil 2] may be ofcomplex construction having two separate sets of windings. If coil 21 isof complex construction, a second pair of terminals 28 and 29 would berequired.

The armature, its pivotal support and the tail spring arrangement, asshown in FIG. I and which will be described briefly herein, is forillustration purposes only and is not intended to define the limits ofthe present invention. A relay construction corresponding to thisillustrative combination of parts is shown, described and claimed in US.Pat. No. 3,201,541 granted Aug. 17, 1965, to me and assigned to the sameassignee as is the present application. It should be further understoodthat recitation of the armature of magnetic material is to be construedin its broadest sense to include a nonmagnetic armature with a plate orlayer of soft magnetic material as is required in the exemplary relayillustrated and described herein.

An armature 30 of soft magnetic material is pivotally supported at oneend on the free end of leg 12 opposite from the base member 11. Armature10 extends from its supported end toward header 25 and terminates in afree end which overlies the exposed surface or pole face 23. A pair oftails or tail portions 31 (only one shown) and a projection 32 spacedbetween the tails extend from the supported end of the armature 30 in adirection away from core 22. The tails 31 are then bent or angledrelative to the major plane of the armature 30 and terminate in freeends which may abut leg 12 and limit the maximum pivotal displacement ofthe armature 30 from the core face 23 which is in a counterclockwisedirection as viewed in FIG. 1. Tail spring 19 which is retained at oneend by projection 18 of the retainer 17, is retained at its other end bythe armature projection 32 and thereby is maintained under tension forbiasing the armature 30 to pivot away from the exposed pole face 23.

A movable contact 36-37 is provided to cooperate with either one of or apair of fixed contacts 26 and 27 to accomplish the relay switchoperation. The contacts are not specific to the present invention.Therefore, only one pair of fixed contacts 26 and 27 with an associatedmovable contact 36-37 will be considered to facilitate description. Aninsulated block means 33 is connected to the armature 30 for mountingthe spring arm 34 of a movable contact. One end of arm 34 extends fromthe mounting means 33 and away from header 25 to provide a connectionterminal 35. Arm 34 also extends axially toward header 25 terminating ina free end disposed between fixed contacts 26 and 27. A pair of contactfaces 36 and 37 are connected to opposite sides of the free end ofspring contact arm 34 to provide the requisite movable contact, and areso arranged that contact face 36 engages contact 26 when the relay isopen or reset and face 37 engages contact 27 when the relay is closed orset.

It should readily be understood that there are substantially threesources of flux, namely, the permanent magnet means 16, theelectromagnet and the remanence of the core 22. Orientation of each fluxsource if it were considered by itself in the absence of such othersources would be unimportant. However, for proper relay operation orresponse the interaction of the magnetic forces derived from all suchsources must be considered which necessitates orientation of each of themagnetic sources relative to the others.

The operation and flux paths of the novel relay are substantially asshown and described in my aforenoted U.S. Pat. No. 3,470,510. Unlike theearlier construction, flux from the bracket member 14 to the pole face23 and/or the core 22 does not cut across the lines of force of thecore. By varying the size of the offset portion 24 of the bracket member14, the pole face 23, which defines the extent of the working airgap,can be provided with an optimum area without sacrificing the corediameter and coil winding relationship of the electromagnet. The moreuniform flux path of the magnetic material of the offset portion 24 thanthat of a remanent magnet reduces the critical location of apoint-to-point contact between the armature member and the pole face 23.To state this another way, the possible reluctance variations across theclosed working airgap depending upon the location of a pointto-pointcontact is substantially eliminated.

In addition to the preferred construction shown in FIGS. 1 and 2, othermodified forms of construction in accordance with the present inventionare shown in the drawings and now will be described.

Referring specifically to FIGS. 3 and 4, a relay (shown in part) isprovided with a modified frame 40 which includes the base member 11 andpermanent magnet 16 of the frame 10. The frame 40 is provided with abracket member 41, of soft magnetic material, with a leg 42 connected tothe magnet 16 corresponding to the bracket member 14 and its leg 15,respectively. Bracket member 41 is provided with an opening 43 insteadof the offset portion 24.

One end of the core 22 of the electromagnet 20 is again connected to thebase member 11 while the other end extends into the opening 43, which isoversized, and terminates substantially flush with the outer surface ofthe bracket member 41. A disclike plate or cap 44 of a soft magneticmaterial is welded or otherwise suitably connected to the end of thecore 22 and the bracket member to provide a magnetic couple and thedesired pole face 45.

Referring now to FIG. 5, a modified frame 50, similar to frame 40 ofFIGS. 3 and 4, is provided with the base member 11 and an L-shapedbracket member 51 of soft magnetic material similar to the bracketmember 41. The bracket member 51 has a leg 52 suitably connected to oneside of the permanent magnet 16, and differs from the bracket 41 onlybecause the opening 43 is eliminated. The core 22 of the electromagnet20 is now welded or otherwise suitably connected between the base member11 and the bracket member 51, and the plate or cap 44 is similarlyconnected to the bracket member in alignment with the core.

All of the construction forms heretofore discussed, one end surface ofthe core 22 is suitably connected to the base member 11 and the otherend surface is similarly connected to the bracket member 14 or 41, orthe plate 44. The area of the pole face 23 or defines or determines theextent of the working airgap and the cooperating face provided by thearmature 30 on the other side of the working airgap opposite from thepole face.

With the core 22 connected between the base member 11 and the bracketmember 51 as shown in FIG. 5, in the absence of the plate 44 thearmature can be used to define or determine the pole face portion of thebracket member 11. One way to accomplish this, as shown in FIG. 6, is toprovide an armature 55 of soft magnetic material with an offset endportion 56 which, in essence, corresponds to the offset face portion 24of FIG. 1. Alternatively, the plate or cap 44 can be suitably connectedto the armature 30 as shown in FIG. 7.

Although several embodiments of the invention have been illustrated anddescribed in detail, it is to be expressly understood that the inventionis not limited thereto. Various changes may also be made in the designand arrangement of the parts without departing from the spirit and scopeof the invention as the same will now be understood by those skilled inthe art.

lclaim:

1. In a clapper-type magnetic latch relay, the combination comprisingframe means including a base member and a bracket member, both of a softmagnetic material;

permanent magnet means connected between said base and bracket members;

electromagnet means including a core of remanent magnet materialmagnetically coupled at one end surface to said base member on one sideof said permanent magnet means, and extending axially from said one endsurface toward said bracket member;

means for magnetically coupling the other end surface of said core tosaid bracket member, and providing a pole face of soft magnetic materialwhich is of a greater area than the cross-sectional area of said core;

a spring-biased clapper-type armature means pivotably supported at oneend by said base member on the one side of said permanent magnet means,and having a free end overlying said pole face and defining an airgaptherebetween; and

said armature means being at least in part of a soft magnetic materialproviding a face at the free end of said armature means and a flux pathbetween said face and said base member.

2. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein said bracket member has a portion thereof offsettoward said armature means and the other end surface of said core isconnected to said offset portion thereby providing said means forcoupling and providing said pole face.

3. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein the free end portion of said armature means isoffset toward said electromagnet means and the other end surface of saidcore is connected to said bracket member thereby providing said meansfor coupling and providing said pole face.

4. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein the other end surface of said core and a platemember of soft magnetic material are connected in axial alignment witheach other to said bracket member thereby providing means for couplingand providing said pole face.

5. In a clapper-type magnetic latch relay, the combination in accordancewith claim 4 and the other end surface of said core and said platemember are connected to opposite sides of said bracket member.

6. In a clapper-type magnetic latch relay, the combination in accordancewith claim 4 wherein said plate member connects the other end surface ofsaid core and said bracket member to each other.

7. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein said bracket member has an opening there throughaxially aligned with and of a larger size than said core;

said core extends into said opening with the other end surface thereofsubstantially coplanar with the surface of said bracket member adjacentthe airgap; and

a plate member of soft magnetic material is connected to said coplanarsurfaces in axial alignment with said core.

8. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein,

alignment with said core thereby providing said means for coupling andproviding said pole face.

1. In a clapper-type magnetic latch relay, the combination comprisingframe means including a base member and a bracket member, both of a softmagnetic material; permanent magnet means connected between said baseand bracket members; electromagnet means including a core of remanentmagnet material magnetically coupled at one end surface to said basemember on one side of said permanent magnet means, and extending axiallyfrom said one end surface toward said bracket member; means formagnetically coupling the other end surface of said core to said bracketmember, and providing a pole face of soft magnetic material which is ofa greater area than the crosssectional area of said core; aspring-biased clapper-type armature means pivotably supported at one endby said base member on the one side of said permanent magnet means, andhaving a free end overlying said pole face and defining an airgaptherebetween; and said armature means being at least in part of a softmagnetic material providing a face at the free end of said armaturemeans and a flux path between said face and said base member.
 2. In aclapper-type magnetic latch relay, the combination in accordance withclaim 1 wherein said bracket member has a portion thereof offset towardsaid armature means and the other end surface of said core is connectedto said offset portion thereby providing said means for coupling andproviding said pole face.
 3. In a clapper-type magnetic latch relay, thecombination in accordance with claim 1 wherein the free end portion ofsaid armature means is offset toward said electromagnet means and theother end surface of said core is connected to said bracket memberthereby providing said means for coupling and providing said pole face.4. In a clapper-type magnetic latch relay, the combination in accordancewith claim 1 wherein the other end surface of said core and a platemember of soft magnetic material are connected in axial alignment witheach other to said bracket member thereby providing means for couplingand providing said pole face.
 5. In a clapper-type magnetic latch relay,the combination in accordance with claim 4 and the other end surface ofsaid core and said plate member are connected to opPosite sides of saidbracket member.
 6. In a clapper-type magnetic latch relay, thecombination in accordance with claim 4 wherein said plate memberconnects the other end surface of said core and said bracket member toeach other.
 7. In a clapper-type magnetic latch relay, the combinationin accordance with claim 1 wherein said bracket member has an openingthere through axially aligned with and of a larger size than said core;said core extends into said opening with the other end surface thereofsubstantially coplanar with the surface of said bracket member adjacentthe airgap; and a plate member of soft magnetic material is connected tosaid coplanar surfaces in axial alignment with said core.
 8. In aclapper-type magnetic latch relay, the combination in accordance withclaim 1 wherein, the other end surface of said core is connected to saidbracket member and a plate member of soft magnetic material is connectedto said armature in substantial axial alignment with said core therebyproviding said means for coupling and providing said pole face.